1# This tells fish to auto-activate my virtualenvs when I change directories.
2#
3# I have a fairly simple naming convention for my virtualenvs: I put
4# them in the root of the Git repo for each project, and I always
5# name them `~/.venv`.  This means it's pretty easy to work out if
6# a virtualenv exists for the current directory.
7#
8# See https://alexwlchan.net/2023/fish-venv/
9#
10function auto_activate_venv --description "Auto activate/deactivate virtualenv when I change directories"
11
12    # Get the top-level directory of the current Git repo (if any)
13    set REPO_ROOT (git rev-parse --show-toplevel 2>/dev/null)
14
15    # Case #1: cd'd into a folder which has a .venv in its root.
16    #
17    # Activate this virtualenv if it's not already activated.
18    if test -d "$(pwd)/.venv"
19        if [ "$VIRTUAL_ENV" != "$(pwd)/.venv" ]
20            source "$(pwd)/.venv/bin/activate.fish" &>/dev/null
21        end
22
23        return
24    end
25
26    # Case #2: cd'd to a folder which isn't a Git repo and doesn't
27    # have a .venv at its root.
28    #
29    # Deactivate any virtualenv which is already active.
30    if test -z "$REPO_ROOT"; and test -n "$VIRTUAL_ENV"
31        deactivate
32    end
33
34    # Case #3: cd'd folders within the same Git repo
35    #
36    # The virtualenv for this Git repo is already activated, so there's
37    # nothing more to do.
38    if [ "$VIRTUAL_ENV" = "$REPO_ROOT/.venv" ]
39        return
40    end
41
42    # Case #4: cd'd from a non-Git folder into a Git repo
43    #
44    # If there's a virtualenv in the root of this repo, we should
45    # activate it now.
46    if [ -d "$REPO_ROOT/.venv" ]
47        source "$REPO_ROOT/.venv/bin/activate.fish" &>/dev/null
48    end
49end